With its white picket fence, Labour red front door and brown plaque commemorating his late wife Caroline, Tony Benn’s house in Notting Hill is something of a local landmark. He has lived here since 1952, mostly downstairs in the basement. There is a small printed note on the front door directing visitors down there. When I find him, the door is open. I ask about the plaque. ‘I put it up myself. Didn’t ask permission. Am too old to ask for permission. Takes too long, asking for permission.’

Too old is 84, though, as I am to discover, everything about Tony Benn, from his demeanour to his idealism, is strangely youthful. Harold Wilson once quipped that Benn ‘immatures with age’, but I think it is more that he is a Benjamin Button, living his political life in reverse.

His grandfather was a Liberal MP, so was his father, before becoming a Labour one. And when Benn first became a Labour MP in 1950, he was quite moderate. By the time he retired in 2001, ‘to devote more time to politics’, he was one of the most radical politicians in his party, and a constant thorn in the side of the Establishment, one remembered for trying to have the Queen’s head removed from stamps. Nowadays, his campaigning tends to be about single issues: he is passionately opposed to nuclear weapons, for example, as well as the European Union and ID cards. He is also the president of the Stop the War Coalition.

But we were talking about his wife, who died in 2000. ‘She was an extraordinary woman,’ he continues in his wuffly voice. ‘An educationalist and writer. I was so shy when I first met her at Oxford. Didn’t propose for nine days. Afterwards I bought the bench I proposed on. Had it in the garden here for years, then when she died, I moved it to our place in Essex, where she is buried. There’s a space at the bottom for my name.’

Benn taps down the tobacco in one of two pipes he alternates between as he talks. He tries lighting it, but without much success, and draws on it regardless. The clicking of the lighters, he has several lying around, seems to be a tic of his, something for him to do with his hands.

When not engaged in this way they flutter like trapped birds. And when he is making a point, which is all the time, his wrists rotate faster. Only when I ask if he ever catches himself talking to his wife when he sits on that bench now does a stillness descend upon him. He stares out of the window. Thinks. ‘Well, you know, you continue communication. Death doesn’t divide you,’ he says.

The basement is dimly lit. In-trays and out-trays teeter with papers and letters. ‘My filing system is messy but orderly,’ Benn says with a shrug. The shelves are laden with political biographies and lever arch files and on his desk there are a number of mugs and pots brimming with pens and pencils.

There are also several cans of butane gas about the place, making it look like a bomb factory. They are for the ubiquitous lighters. He still hasn’t eaten meat since becoming a vegetarian in 1970, still hasn’t touched a drop of alcohol in his life and still drinks about a pint of tea an hour. Teetotal indeed.

‘My whole life is in this room really. I come down at seven and go to bed at midnight. I don’t have a secretary so there are thousands of emails and letters to deal with. Very satisfying. Really enjoying life,’ he says. Benn’s idea of a dream day is speaking to all four of his children on the phone, which he usually does, and having his 10 grandchildren popping in and out. ‘My day rotates around my family. I am very lucky. Hilary [his son, the environment secretary] rings twice a week. We’ve never fallen out over politics. He said when he was elected that he was a Benn, not a Bennite. And so am I.’

Benn sometimes does his contributions to the Radio 4 Today programme from this basement, too, but more often he goes over to the studio in White City. While we are talking, his phone rings regularly, and one of the calls is from the Jeremy Vine Show on Radio 2. They want him on at lunchtime to talk about the moon landings. Often, he says, the calls these days are requests from obituary editors wanting a quote about people he has known.

For he has known everyone, from Ramsay MacDonald and Oswald Mosley to Ghandi and Mandela. His circle of friends has included Enoch Powell on one end of the political spectrum and Arthur Scargill on the other. He was, furthermore, the last Westerner to interview Saddam Hussein, a few weeks before the war. ‘I wanted to ask him to his face whether he had WMDs. He told me he didn’t. Turned out he was telling the truth.’

Benn’s compulsive diary keeping, he reckons, is to do with a moral responsibility he feels to give an account of his life. ‘I will present the Almighty with 18 million words and say, what do you make of it? I can’t go to bed if I haven’t done my diary. I always record them just as I’ve always recorded all my interviews and speeches,’ he says.

‘Experience is the only real teacher and if you keep a diary you get three bites at educating yourself – when it happens, when you write it down, and when you reread it and realise you were wrong. Making mistakes is part of life. The only things I would feel ashamed of would be if I had said things I hadn’t believed in order to get on. Some politicians do do that.’

Example? ‘Neil Kinnock. When he started in 1970 he wrote to me saying he believed everything I believed. Politicians are divided into signposts and weathercocks. Neil Kinnock gave up everything he believed in to get power and ended up with no one believing him about anything. That makes him a weathercock. Margaret Thatcher was a signpost. The trouble was, I thought her sign pointed in the wrong direction. She was not affected by spin-doctors, she said what she meant and people knew what they were voting for. I see myself as being more of a signpost, like her,’ he says.

Benn talks in aphorisms like these, as well as self-detracting anecdotes, well polished from his popular stage show: An Evening with Tony Benn. Given all his years of experience (as well as being an MP for 51 years he was also a cabinet minister, first in the Sixties, then again in the Seventies), I ask whether the political world still has the capacity to surprise him. What does he make of the current low standing of MPs following the expenses scandal?

‘I think you should always be suspicious of people who want power. I don’t mean cynical, but someone who has power is someone you have to watch carefully,’ he says. ‘When my father was elected there was no pay for MPs at all. He was a journalist who went to the House in the afternoon. The interesting thing for me about the expenses scandal is that it shows the importance of having a Freedom of Information Act. If that had been around at the time, no one would have been claiming expenses. The government want to know everything about us, but it doesn’t want us to know about them.’

Benn doesn’t miss the House of Commons, but he does miss his weekly surgeries. ‘Being a politician is the only job where you have one employee and 65,000 employers. I do miss that,’ he says.

Even Benn’s enemies would have to admit he has beautiful manners. He is always courteous, however heated the debate. ‘Well, I don’t believe you should attack people personally,’ he says. ‘My father taught me that. Democracy is about competing opinion, but you don’t have to be nasty about it. The personality side of things switches me off completely. I stopped reading the papers when they were full of all these personal attacks on Gordon Brown. What matters is what is done, not who does it.’

He was a victim of the personalisation of politics himself. The Sun constantly vilified him in the Eighties, running ‘Benn on the couch’ features that questioned his sanity. ‘It was very unpleasant. My black sacks of rubbish were collected every day in a Rover car. Now I know the Kensington Borough Council is Conservative and very efficient, but I don’t think they were that efficient,’ he says. ‘That car was being driven by The Sun presumably, or MI5. My son invented a rubbish bell so that when the sacks were lifted a bell rang and we could see who was taking it away.’

He also became convinced that MI5, or someone, was bugging his phone. Did he begin to question his own sanity? ‘No, never. But they always do this. If you argue for progressive change you are ignored at first, then you are dismissed as mad, then dangerous, then there is a pause and you can’t find anyone at the top who doesn’t claim that it was their idea. Watching those stages is a good way of analysing how far you have got with your cause.’

And the smears? ‘There is always some of that. They said I had a bank account in the Bahamas and I thought: Really? I had better write to the bank and ask for the money back then. My family suffered. Had to train the children how to deal with being photographed on their way to school. The photographers would eff and blind at the children in the hope that they would react. A horrible experience,’ he says.

In retirement, Benn seems to have acquired something that always eluded him as a working politician: likeability. He is still not clubbable exactly, but he does suit the role of sage. And the popularity of his theatre talks is a testament to the broad affection in which he is now held, and not only by those on the left. What is perhaps most extraordinary is his popularity among the young. In 2002, he captivated audiences at Glastonbury with his political talks.

To what does he attribute this? ‘I would like to be remembered as someone who encouraged people, that is all. When I talk to young people I say: “I owe you an apology because my generation made such a muck of the world, killing 100 million people in two world wars. Your generation has to get it right”.’

He sucks on his pipe. ‘I think Ali G did me a huge amount of good with the young. He came to this house and completely took me in and I argued with him when he said “bitches only get pregnant in order to get benefit” and “people only go on strike to chill out”. And I said: “Don’t be ridiculous”.You see, a lot of the people he interviewed were frightened of him.’

But as Benn was so confident that he was neither racist nor sexist, did that mean he was able to stand up to Ali G? ‘Yes and when I was told it was a hoax, I was furious. But then when I saw it and saw what he had done with the other interviews, I found it hilarious. He’s my main man!’

He is chuckling now. Before things become too cosy, I turn to a subject about which Benn is known to be prickly. There is an immoral equivalence between fascism and communism, I argue, because of the genocide committed in the name of both. Yet while the BNP is rightly vilified for its association with fascism, Socialist parties are not vilified for their association with communism. Why is that, does he suppose?

He stares at me indignantly. ‘Socialism? Socialism is a democratic idea. The most socialist thing we ever did was the most popular thing we ever did, the NHS.’ But isn’t socialism just a polite version of communism? ‘Oh that’s just the media. The two attempts at socialism in my lifetime have failed because the communists weren’t democratic, and the social democrats adopted capitalism. Margaret Thatcher said Tony Blair and New Labour was her greatest achievement, and she was right,’ he says.

Benn quotes Mein Kampf, a passage in which Hitler writes that democracy leads to Marxism. Yes, I say, but doesn’t Marxism always lead to dictatorship? ‘Good heavens no. Marx was a philosopher. Think of the things that have been done in the name of Christ. The Pope stole Christianity from Jesus and Stalin stole Marxism from Marx. All Marx said was the world is divided between the 95 per cent who create the wealth and the five per cent who own it. That was an explanation, like Darwin.’

Last autumn, when the banks were part nationalised, did that seem like a Marxist moment to him? ‘Not at all. A classic case of the state funding capitalism. If it were Marxism you wouldn’t have this continuation of the bonus culture. The economic crisis we have now is a product of Thatcherism and Blairism applied to the economy. No one has said the trade unions are responsible for the credit crisis.’

Does he now accept that the unions abused their power though? ‘Well they used to be described as the barons of the TUC, but barons don’t get elected. Emperor Jack was elected, unlike Rupert Murdoch. I think we do live in a one-party state in that all three parties believe socialism has failed and capitalism has somehow got to be made to work, and it hasn’t worked.’

His 19-year-old granddaughter Emily may be about to become the fifth generation of the Benn family to enter politics, having been selected for the seat of Worthing and Shoreham. ‘I went to speak for her the other day. Very bright girl. The interest in politics runs in the family. Both my grandfathers were MPs, as was my dad and my son,’ he says.

He had tears in his eyes when he spoke for her. Has he become more emotional with age? ‘Oh yes, I burst into tears at the drop of a hat. When I introduced my son in parliament, my family were in the gallery and they said: “It’s The Railway Children all over again.” I always cry in that,’ Benn says.

‘There is nothing wrong in crying, and laughing. The tight-lipped Englishman is a totally artificial construct. I think bottling up emotions is so unnatural. Why are we given strong emotions if they are not to be expressed? Hating people damages you and doesn’t damage the people you hate, and if you hate someone it makes you unhappy and doesn’t affect them.’

He may not hate people, but are there things he hates? ‘I hate war. War is murder, rape, torture and plunder. Churchill was right, jaw jaw is always preferable. But I’m not a pacifist. I believe in the right of self-defence. I joined the RAF in the war but didn’t get my wings until the end so never had to kill anyone.’

His older brother Michael died in the war, while serving with the RAF. ‘I think of him every day.’ He shakes his head. ‘Every day. I got the telegram at the beginning of an RAF training class about weather and I had to sit there for an hour and then I went outside and wept. I remember him writing to me and saying he had shot down a German plane and he was thinking of the German’s family. He wanted to be a Christian minister.

‘You can never fill the gap that’s left, but you can decorate the gap with the flowers of memory. Everyone dies. At funerals I think: here we all are grieving this person but in a hundred years’ time everyone in this church will be dead. All that is left is memory and what you remember is the things people did in life. You remember the people who helped you lead a better life, the great artists, thinkers, leaders.’

He stares at a pigeon eating grain in his back garden. There are 12 of them who come every morning. ‘I go outside and say: “Birdies”, then throw down some seeds. I also leave some nuts out for a squirrel who comes. Then a cat comes round and scratches at the window. It is a way of having pets without the responsibility.’

I ask whether he thinks Enoch Powell was right when he said all political careers end in failure. ‘Not in my case because I was a failure much earlier on. I was attacked all the time. Everything I did was denounced. In old age people are much kinder. Also I don’t want anything anymore. I don’t want your vote, and that is a great strength,’ he says. ‘You become a Buddhist by default because you rid yourself of desire. If I had known what fun it was to be 84 I would have done it years ago.’

Perhaps his career hasn’t ended in failure, but in a worse fate – he has been sentimentalised by the public. ‘That is the worst corruption, to become regarded as a kindly, harmless old gentlemen. Well, I am kindly and I am old, but I am not harmless.’ He chuckles. ‘I got a death threat last year. Hadn’t had one for years. I was so chuffed.’

J.

James Blunt

It could be the homes around the world; his military bearing; or that he’s our biggest musical export since Elton. For whatever reason, being called annoying, a philanderer or – worse – middle class doesn’t exactly keep James Hillier Blount awake at night. Nigel Farndale met him

It’s not the sight of the groupies that haunts me, but the sound, or rather the absence of sound, as they ghost past us on their way up the stairs to the dressing-room. It takes me a moment to figure out that the reason they aren’t talking to each other is that they don’t know each other. One of the band members, the keyboard player, I think, has picked them from the audience on the basis of their looks. Half-a-dozen of them, all in their late teens and early twenties, and all, surprisingly, in pretty frocks, as if they were going to a Sunday school meeting. They have been separated from their friends like lambs weaned from their mothers. The silence of the lambs.

The ‘us’ they are filing past is James Blunt and me. He has a bottle of beer in one hand, a cigarette in the other, and not a hair in place – tousled just so, like a Renaissance painting of John the Baptist – but they don’t realise it’s him because he has changed out of the suit he was wearing on stage and is now in jeans, T-shirt and leather jacket, as well as a pink feather boa and star-shaped novelty sunglasses. But I’m getting ahead of myself. This is the end of the day; we need to go back to the start, well, to the middle, when the seats are empty and the Texan sun is at its most unforgiving.

A barefoot and unshaven Blunt is wearing normal sunglasses and shorts as he plays his piano, strums his guitar and sings his plaintive songs into the microphone for the sound check, all the while looking out with his soulful eyes over an empty, open-air arena in Houston. At 5ft 7in, he’s not a tall man, but he has presence and an unaffected manner – a certain maturity, too, one that you wouldn’t normally associate with a pop star in the ascendant.

But then he is 34 and this is his second career, his first being as an officer in the Household Cavalry. He joined after graduating from Bristol University with a degree in sociology. He became a champion skier for the Army and not only saw active service in Kosovo, but also guarded the Queen Mother’s coffin when she was lying in state.

Tonight he will be supporting Sheryl Crow, though, since his second album ‘All the Lost Souls’ and the single from it, ‘1973’, went straight to number one in America, he is arguably the bigger act these days. Indeed, not since Elton John has there been a more successful British singer-songwriter in the States.

His first album, ‘Back to Bedlam’, also went to number one over here, as it did in 18 other countries, making it the biggest-selling album of the millennium. It even entered the Guinness Book of Records as the fastest-selling album in one year. But it was his first single that really put him on the map. You’re Beautiful became the sound of that summer. It was everywhere, and still is – having become a favourite at weddings, funerals and bar mitzvahs. I even heard a brass band playing it at an agricultural show in the Yorkshire Dales this summer.

As well as millions of sales, James Blunt has won Brit awards, Ivor Novello awards, MTV awards and various Grammy nominations. In terms of credibility, he’s headlined at Glastonbury and won the respect of the world-weary music press. Yet not everyone loves him, as he points out when we get something to eat in the canteen area back stage.

‘After Back to Bedlam really started selling,’ he says, ‘there was this sudden aggression towards me in the UK, for whatever reason, and that focused my mind, made it clear to me what I was doing and why I wanted to do it. I write songs for myself. I don’t write them for you, or for anyone else, I write them because I have experiences that I need to process. I don’t have the answers all the time, but I do have lots of questions, and I express them in the songs I write.’

He is, I think, alluding to a poll last year of ‘the most annoying things in life’, which put him at number four, just behind cold-callers and queue-jumpers. ‘I haven’t met anyone who voted in the poll, have you?’ he says when I mention this. ‘That poll probably came from a website that was after some publicity. You and I could do the same poll very quickly right now and it would count as a poll. We could do one about annoying newspapers, for example. I promise the Sunday Telegraph wouldn’t be in my list. My parents take it.’

His father, a retired colonel in the Army Air Corps, manages his son’s finances. His mother arranged the purchase of his six-bedroom villa in Ibiza (he also has a chalet in Verbier and recently bought a place in Chelsea). ‘I’m not married,’ he says, ‘and so the support structure in my life is my parents. I’m closer to them now than I have ever been.’

He certainly isn’t married, as the photographs of him emerging from nightclubs with various high-profile women on his arm attest. Tara Palmer-Tomkinson was probably the best known socialite, Jessica Sutta, of the Pussycat Dolls, the most glamorous. He also seems to be photographed regularly cavorting on beaches with bikini-clad models such as Petra Nemcova, whom he dated and then dumped – unceremonious dumping being his way of ending relationships, according to the tabloids. He once said he found himself in a swimming pool in LA with nine naked women. ‘I was the only bloke. It was the only time I wished my mates were there, purely to spectate. I had arrived. It was a moment.’

Now he says of the tabloid interest in his peripatetic love life: ‘Last week I went to my home in Ibiza and was photographed by the paparazzi in my swimming trunks with girls. What is the point of that? I’m not that bothered, but maybe the media should be concentrating more on global warming or the Russian invasion of Georgia.

‘Looking at me in my swimming trunks is not a great sight. It’s a waste of time. There generally is a long lens pointing at me wherever I go, these days. I’m comfortable with it. I appreciate how things work. But my record label said something about my always being photographed coming out of nightclubs and I thought, “But this is what I do. I was doing it before the second album came out, so what is different now? You didn’t tell me to stop then.” I’m not going to change my life because of these people. I don’t see why I should.’

His label also gets him to dye his grey hairs and be enigmatic about his love life, which is an old tactic dating back to the Beatles – they had to pretend they didn’t have wives and girlfriends so that fans could fantasise they were in with a chance.

Actually, at the time of going to press, Blunt seems to be going out again with one of his old flames, Verity Evetts, an Oxford-educated barrister. He has also stayed friendly with some of his other exes, the socialites at least. He told one – an ex who got married not long ago – that he doesn’t feel ‘centred’ at the moment and would like to get married as well. Then again, he also said that he never tires of singing You’re Beautiful night after night because it gets him laid night after night.

Either way, he tells me he has grown used to the idea that his mother will probably find out from the papers what he has been up to, and with whom, before he has had a chance to tell her. ‘And my [two] sisters are quick to email me about things in the papers, laughing their heads off. I get healthy, ritual abuse from them, and give it back myself.’

As we are talking, I can’t decide whether the way Blunt smiles all the time is disarming or disturbing. He’s like a victim of a religious cult, smiling at the beginning of the sentence and at the end. I guess he has a lot to smile about, but also I sense a great deal of insecurity to disguise.

Then, I’m distracted by the sight of Sheryl Crow playing table tennis across the room. She has been holding her adopted son in one arm as she bats with the other, and now, even more distractingly, she is heading straight for us. ‘Are we going to have one of our little conversations on stage again tonight, James?’ she says. ‘That flirting thing. I think it worked well last night.’

They discuss the duet they will sing – a cover of Cat Stevens’s The First Cut is the Deepest – then we both watch her shimmy away, her blonde curls bobbing. ‘She’s very down to earth,’ he says. ‘I’d met her a couple of times, which was why she asked me on this tour. We do end up playing a lot of table tennis on the road. We’ve done 117 shows so far this year, in 117 cities, and there are a lot of hours to fill in the day.’

As he sleeps on his tour bus with his band, one city tends to blur into another. When I joke that he is in Cincinnati now, he looks genuinely confused. ‘No, this is?… Oh, right. Actually, I always get the tour manager to say where we are just as I’m going on stage. I still managed to get it wrong the other night, saying “Hello Dallas” when I meant Austin. I’m surprised I got out alive.’

He is funny on the subjects of things that go wrong. ‘People are normally surprised by my show, which is more energetic than you might think. Jumping on the piano. Jumping out into the audience and running up and down the aisle high-fiving them. But going off the stage can be quite dangerous. I broke my finger once. My legs carried on when I jumped off, and I smacked down on the ground. The spotlight was on me, and when I got back to the piano I hit the wrong note and thought, “Why did I do that?” And I looked down and saw it was because my finger was broken, sticking out an angle. Look,’ he says holding it up. ‘It’s still crooked.’

On another occasion, in Chicago, he jumped 8ft off the stage. ‘When I began running to the audience, a security guard stuck his arm out and I thought, “Does he want a hug?” Then next thing I know he’s rugby-tackled me. He wouldn’t release me and I was screaming in his ear, “I’m the f—ing singer.” I had to wait for the other guards to pull him off.’

I would have thought Blunt’s training in unarmed combat would have helped. I presume he still works out. ‘No, never. Couldn’t handle it. Too boring. I am a hyperactive person though.’ He likes an adrenaline rush, as well, having recently bought an 1100cc Moto Guzzi V11 Sport motorbike. There’s also the skiing, which he still does, and the riding. Actually, he tells me, he never really liked horses before joining the Life Guards. So why did he join that particular regiment?

‘Well, it is a reconnaissance regiment.’ But they are all so tall in the Life Guards, did that not make him self-conscious? ‘Some are. The Foot Guards tend to be taller regiments, though. The Life Guards take a few shrimps, as well. Besides, they are on horses, so height isn’t so important. Also being in that regiment had the benefit of being in Knightsbridge. I got a chance to be in London and meet people in the music scene.’ And groupies, as it happens.

As he paraded up and down the Mall in plumed helmet and shiny breastplate, girls would stick their phone numbers down his knee-length boots. But it was his time in Kosovo that really made girls swoon. He used to strap his guitar to the outside of his tank, because there wasn’t room for it inside. He had learnt to play the violin at five, the piano at seven and the guitar at 14, while a pupil at Harrow.

He writes his songs on piano and guitar. ‘But mainly guitar because it is easier to carry around. It’s like a child messing around with a toy. If a tune comes to me I don’t record it instantly. I think if I remember it, then it must be worth remembering, and if I forget it, then it was forgettable.’

Does he have any anxiety dreams about forgetting lines or chords? ‘Not yet. Perhaps I will tonight. Perhaps you’ve jinxed me. But audiences aren’t judgmental, and if things go wrong and you can look them in the eye, that is fine. The only people who are judgmental are the journalists. I will be conscious of you being there in the audience judging me.’

Blimey. Sorry about that. Is it true he signs breasts? ‘Not that I remember. Not that I’m fussy what I sign. A lot of men started coming to the shows after I appeared on Top Gear last year. That was such fun. I spun the car five times. I thought I might as well make the most of it. I am competitive.’

He recorded one of the fastest laps, but I’m surprised blokes didn’t think him manly before that, given his tour of duty in Kosovo. ‘It’s because I sing songs that are heart-on-your-sleeve and therefore I must be overly emotional. Nothing I can do about it. I could pose more, but I am comfortable with my masculinity.’

He has said that his lyrics are autobiographical, in which case, are we to assume that the lyric on his new album, ‘I killed a man in a far away land’, means he killed a man in a far away land? I only ask because in the past he has said that he would never try to exploit what he went through, what he saw. ‘You should ask any soldier how many lives he has saved. How they do it is no one else’s business. What I took from my experience in Kosovo is that you are told from one day to the next who your enemy is and it keeps changing. That’s what is happening in Iraq, too. I believe in looking people in the eye, looking for the common humanity.’

He is a great believer in looking people in the eye. He will use the phrase again later and it seems to reveal a Christ complex, or a John the Baptist one. That direct and challenging stare of his. It would also explain the hair.

It is time for him do some photographs before he goes on stage and, endearingly, he says he is ‘not fussed’ about the grooming he is offered before they are taken.

On stage his features contort with passion when he sings. The big video screen goes in tight on his face. His voice is by turns soft and tremulous and forceful, but always high. Having seen him in concert once before, a couple of years ago, I notice the tone of his banter has changed.

‘Wow it’s hot tonight,’ he says now. ‘I’m surprised any of you are wearing any clothes. We could all take them off and get friendly.’ It is suggestive, designed to get the teenage girls in the audience screaming. Before he used to joke about his ‘girlie voice’ and taking helium to get it that way, and being ‘a bit wet’ and the ‘housewives’ favourite’. I think now he has realised that, actually, he is a proper musician, a popular one, too, and that he doesn’t need to apologise for it.

Afterwards, back in the dressing-room, he strips to the waist as he talks because he wants to take a shower before going back on to do his duet with Sheryl Crow. ‘Things got a bit hairy out there when I jumped into the crowd,’ he says. ‘Did you see that? Some thought it was some kind of sport to grab me.’

I watch his duet from the side of the stage and notice he whispers something in Sheryl Crow’s ear and then she starts running her hands over his trousers suggestively, patting them. Afterwards, I ask what he said. ‘”Is now a good time to ask for your phone number?” She was checking my pockets, pretending to look for a pen.’

He shows me round the gold-coloured tour bus where he will be sleeping tonight as they drive to their next gig in Dallas. It is full of hi-tech equipment and is nicely air-conditioned but there isn’t much space in the bunks. ‘We do live in close proximity,’ he says. ‘Some of us stay up late. This is the crew end, they have to get up early.’

Where do the groupies go? ‘Never have groupies on here. Never. They’d only get in if we invited them in. But we’d only ever invite friends in.’

Does he sleep OK? I heard he has to take sleeping pills. ‘It is a bit of a rough sleep, but better than a hotel and taking planes all the time because you have to get to the airport two hours early, which is miserable. Then your flight gets delayed.’

He is drinking champagne from a plastic cup. ‘This is for your benefit,’ he says. ‘The tour management went out and bought a bottle of champagne because he thought I should be seen drinking it. Better for my image. Isn’t that sweet? Normally, we drink vodka and beer. In fact, I think I’d rather have a beer, now. Want one?’ He opens a well-stocked fridge then takes me to the back of the bus where there is some seating space. He has one small case which he pulls out from a cupboard. It continues a few pairs of socks, T-shirts and a spare pair of jeans. No photographs or mementos. ‘This is all I have for 14 months on the road,’ he says. ‘I’m not known for style.’

Does he know how much he is worth? ‘No I don’t, not very interested in it to be honest. I travel with hand luggage only. That is why I always seem to be wearing the same clothes in photographs. If a tabloid says my clothes aren’t fashionable or my hair looks stupid, I really don’t worry about it. Don’t have any hair gel.’

In London, he takes the Tube or the bus. He prefers pubs to restaurants. When he goes to Ibiza, he flies easyJet. Still, that’s at home. Presumably on the road he can afford to be more self-indulgent.

Another lyric that we can only assume is autobiographical is ‘I’ve taken a s—load of drugs’. It is. Though his only comment on the subject is that he has ‘a comfortable relationship with drugs’. His relationship with fame is less comfortable. Oscar Wilde said there were two forms of tragedy: not getting what you want, and getting it. Is that how it felt for him when he went to number one? ‘Actually, I don’t think I had been dreaming about it. Certainly, I hadn’t anticipated being so recognisable so quickly.

‘I do remember getting a phone call from the record company, who said both the single and the album have gone to number one, and thinking, “S—, this is not what I expected.” I hadn’t prepared myself for it. Number two is great. Number two is nice. I sensed then it would mean having to change from being a musician to being a celebrity and that that would be a change for the worse. Fame doesn’t affect me, but it does affect everyone else around me. As for celebrity, it is the worst invention of the modern world. Gossip columns treat your life as if it were a cartoon. Relationships reduced to cartoons.’

Although there are other public-school bands around at the moment – Radiohead, Coldplay – Blunt seems to have suffered more than most from a perception that he is too posh to be credible. His family name is Blount (and his middle name Hillier), but he changed it to Blunt to sound, well, blunter and more proletarian.

When he tells me he would nevertheless still send a son of his to Harrow – ‘I think I would. I think I would. Public schools make individuals rather than sheep’ – I ask what he makes of the mood change now that the old Etonian David Cameron has made it OK to be posh. ‘Is it? I must come back to Britain immediately. Is it really safe to come back?

‘It’s not a dirty word to be posh, people come up to me and no one gives a damn if I’m posh. It’s about having a normal conversation and looking people in the eye.’

We head back to the dressing-room where he puts on his feather boa and novelty sunglasses then we wander back downstairs to have a word with Sheryl Crow, who is signing autographs. This is the moment at which the keyboard player says: ‘This way to the good-time room girls’ and the silent groupies dutifully appear.